This invention relates to trenchers, and specifically to trenchers which are utilized in conjunction with a motorized vehicle.
Trenchers have existed for many years. Trenchers have been designed as independent units which are coupled to a tractor or other vehicle for relocation purposes only, as shown in U.S. Pat. No. 2,817,167. These units have internal combustion engines coupled to an endless loop chain having a series of buckets or digging teeth. The endless loop chain is guided upon a boom or cutting bar. Because of the weight and size of these units, they tend to be very difficult to maneuver and operate.
Trenchers have also been designed to operate in conjunction with a motorized vehicle. These trenchers typically have hydraulic motors which actuate the endless loop chain, as shown in U.S. Pat. Nos. 3,754,341 and 3,398,471. Typically, the hydraulic motor of these trenchers is coupled to a hydraulic pump coupled to the internal combustion engine of the vehicle. As such, hydraulic lines extend between the vehicle and the trencher. These hydraulic lines, as well as other mechanical linkage between the vehicle and the trencher, must be disconnected when removing the trencher from the vehicle so that the vehicle may be used for other purposes. Because of the high pressure of the hydraulic fluid within these hydraulic lines the disconnection of the trencher from the vehicle has proven to be difficult and dangerous.
Trenchers have also been designed with mechanical linkages between the internal combustion engine of the vehicle and the trenching chain, as shown in U.S. Pat. Nos. 3,130,506 and 4,833,797. This linkage typically consists of a drive train and a plurality of coupling bars. Again, it is oftentimes a difficult task to disconnect the trencher from the vehicle due to the existence of these mechanical linkages. Furthermore, once the trencher is removed, the remaining linkage coupled to the vehicle must oftentimes be removed in order for the vehicle to operate properly and safely.
Accordingly, it is seen that a need remains for a trencher which may be quickly and easily connected to and later disconnected from a vehicle. It is to the provision of such therefore that the present invention is primarily directed.
In a preferred form of the invention a combination trencher and vehicle comprises, in combination, a mobile vehicle having a plurality of wheels and an internal combustion engine operatively coupled to at least one of the wheels, a first coupler portion mounted to one end of the vehicle which is operatively coupled to the internal combustion engine and which has a rotating first coupling member, a carriage releasably coupled to the vehicle, a second coupler portion coupled to the carriage which has a rotating second coupling member configured to mate releasably with the first coupling member of the first coupler portion, a hydraulic pump operatively coupled to the second coupling member, a hydraulic motor hydraulically coupled to the hydraulic pump, digging means including an endless loop digging chain coupled to the carriage and drivably coupled to the hydraulic motor, and control means hydraulically coupled to the hydraulic pump and the hydraulic motor for controlling the operation of the hydraulic motor. With this construction, the carriage may be disconnected from the vehicle and the second coupling means disconnected from the first coupling means to remove the digging means quickly and easily from the vehicle.